It’s a web app for designing pendants called The Variable Cross. Dolf Veenvliet (aka macouno) emailed me about it yesterday:

The Variable Cross is a pendant that you can customise through a webpage in 3D. The website uses brand new WebGL technology (works best in Chrome). You can then get a Sterling Silver 3D printed real life version of the very pendant you designed. As far as I know I am the first to offer you the tools to create your own jewellery in precious metals using 3D printing. And all without needing any special skills.